基于C++ Qt+FFMPEG+SDL2写的视频播放器源代码，可以播放本地视频

#include "AVUtils.h" bool AVUtils::isInit = false; AVUtils::AVUtils() : mPlayerState(VideoPlayer_Stop), mConditon_Audio(new WaitCondition), mConditon_Video(new WaitCondition), mAudioID(0), mIsNeedPause(false), mVolume(1), mIsQuit(false), mIsMute(false), mIsPause(false), mPauseStartTime(0) { init(); } AVUtils::~AVUtils() { av_lockmgr_register(NULL); avformat_network_deinit(); } bool AVUtils::init() { if (!isInit) { av_register_all(); avformat_network_init(); isInit = true; } return isInit; } bool AVUtils::start(std::string filePath) { if (mPlayerState != VideoPlayer_Stop) return false; mIsQuit = false; mIsPause = false; if (!filePath.empty()) this->filePath = filePath; std::thread([&](AVUtils *avutils) { avutils->readVideoFile(); }, this).detach(); return true; } bool AVUtils::replay() { stop(); start(filePath); return true; } bool AVUtils::play() { if (mPlayerState != VideoPlayer_Pause) return false; mIsNeedPause = false; mIsPause = false; uint64_t pauseTime = av_gettime() - mVideoStartTime; //暂停了多长时间 mVideoStartTime += pauseTime; //将暂停的时间加到开始播放的时间上，保证同步不受暂停的影响 mPlayerState = VideoPlayer_Playing; doPlayerStateChanged(VideoPlayer_Playing, mVideoStream != nullptr, mAudioStream != nullptr); return true; } bool AVUtils::puase() { mIsPause = true; if (mPlayerState != VideoPlayer_Playing) return false; mPauseStartTime = av_gettime(); mPlayerState = VideoPlayer_Pause; doPlayerStateChanged(VideoPlayer_Pause, mVideoStream != nullptr, mAudioStream != nullptr); return true; } bool AVUtils::stop(bool isWait) { if (mPlayerState == VideoPlayer_Stop) return false; mPlayerState = VideoPlayer_Stop; mIsQuit = true; if (!isWait) return true; while (!mIsReadThreadFinished) QThread::msleep(5); return true; } void AVUtils::seek(int64_t pos) { if (!seek_req) { seek_pos = pos; seek_req = 1; } } void AVUtils::setMute(bool isMute) { this->mIsMute = isMute; } void AVUtils::setVolume(float value) { mVolume = value; } float AVUtils::getVolume() { return mVolume; } int64_t AVUtils::getTotalTime() { if (pFormatCtx != nullptr) return pFormatCtx->duration; return 0; } double AVUtils::getCurrentTime() { return audio_clock; } VideoPlayerState AVUtils::getState() { return this->mPlayerState; } void AVUtils::readVideoFile() { ///SDL初始化需要放入子线程中，否则有些电脑会有问题。 if (SDL_Init(SDL_INIT_AUDIO)) { doOpenSdlFailed(-100); fprintf(stderr, "Could not initialize SDL - %s. \n", SDL_GetError()); return; } mIsReadThreadFinished = false; mIsReadFinished = false; const char* file_path = filePath.c_str(); pFormatCtx = nullptr; pCodecCtx = nullptr; pCodec = nullptr; aCodecCtx = nullptr; aCodec = nullptr; aFrame = nullptr; swrCtx = nullptr; mAudioStream = nullptr; mVideoStream = nullptr; audio_clock = 0; video_clock = 0; int audioStream, videoStream; //Allocate an AVFormatContext. pFormatCtx = avformat_alloc_context(); AVDictionary* opts = NULL; av_dict_set(&opts, "rtsp_transport", "tcp", 0);//设置tcp or udp，默认一般优先tcp再尝试udp av_dict_set(&opts, "stimeout", "60000000", 0);//设置超时3秒 if (avformat_open_input(&pFormatCtx, file_path, nullptr, &opts) != 0) { fprintf(stderr, "can't open the file. \n"); doOpenVideoFileFailed(); goto end; } if (avformat_find_stream_info(pFormatCtx, nullptr) < 0) { fprintf(stderr, "Could't find stream infomation.\n"); doOpenVideoFileFailed(); goto end; } videoStream = -1; audioStream = -1; ///循环查找视频中包含的流信息， for (int i = 0; i < pFormatCtx->nb_streams; i++) { AVMediaType media_type = pFormatCtx->streams[i]->codec->codec_type; if (media_type == AVMEDIA_TYPE_VIDEO) { videoStream = i; } else if (media_type == AVMEDIA_TYPE_AUDIO) { audioStream = i; } if (videoStream > 0 && audioStream > 0) { break; } } doTotalTimeChanged(getTotalTime()); ///打开视频解码器，并启动视频线程 if (videoStream >= 0) { ///查找视频解码器 pCodecCtx = pFormatCtx->streams[videoStream]->codec; pCodec = avcodec_find_decoder(pCodecCtx->codec_id); if (pCodec == nullptr) { fprintf(stderr, "PCodec not found.\n"); doOpenVideoFileFailed(); goto end; } ///打开视频解码器 if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) { fprintf(stderr, "Could not open video codec.\n"); doOpenVideoFileFailed(); goto end; } mVideoStream = pFormatCtx->streams[videoStream]; ///创建一个线程专门用来解码视频 std::thread([&](AVUtils* avutil) { avutil->decodeVideoThread(); }, this).detach(); } if (audioStream >= 0) { ///查找音频解码器 aCodecCtx = pFormatCtx->streams[audioStream]->codec; aCodec = avcodec_find_decoder(aCodecCtx->codec_id); if (aCodec == NULL) { fprintf(stderr, "ACodec not found.\n"); audioStream = -1; } else { ///打开音频解码器 if (avcodec_open2(aCodecCtx, aCodec, nullptr) < 0) { fprintf(stderr, "Could not open audio codec.\n"); doOpenVideoFileFailed(); goto end; } ///解码音频相关 aFrame = av_frame_alloc(); aFrame_ReSample = nullptr; //frame->16bit 44100 PCM 统一音频采样格式与采样率 swrCtx = nullptr; //输出的声道布局 out_ch_layout = av_get_default_channel_layout(audio_tgt_channels); ///AV_CH_LAYOUT_STEREO out_ch_layout &= ~AV_CH_LAYOUT_STEREO_DOWNMIX; /// 这里音频播放使用了固定的参数 /// 强制将音频重采样成44100 双声道 AV_SAMPLE_FMT_S16 /// SDL播放中也是用了同样的播放参数 //重采样设置选项---------------- //输入的采样格式 in_sample_fmt = aCodecCtx->sample_fmt; //输出的采样格式 16bit PCM out_sample_fmt = AV_SAMPLE_FMT_S16; //输入的采样率 in_sample_rate = aCodecCtx->sample_rate; //输入的声道布局 int in_ch_layout = aCodecCtx->channel_layout; //输出的采样率 //out_sample_rate = 44100; out_sample_rate = aCodecCtx->sample_rate; audio_tgt_channels = 2; ///av_get_channel_layout_nb_channels(out_ch_layout); out_ch_layout = av_get_default_channel_layout(audio_tgt_channels); ///AV_CH_LAYOUT_STEREO out_ch_layout &= ~AV_CH_LAYOUT_STEREO_DOWNMIX; if (in_ch_layout <= 0) { in_ch_layout = av_get_default_channel_layout(aCodecCtx->channels); } swrCtx = swr_alloc_set_opts(nullptr, out_ch_layout, out_sample_fmt, out_sample_rate, in_ch_layout, in_sample_fmt, in_sample_rate, 0, nullptr); int ret = swr_init(swrCtx); if (ret < 0) { char buff[128] = { 0 }; av_strerror(ret, buff, 128); fprintf(stderr, "Could not open resample context %s\n", buff); swr_free(&swrCtx); swrCtx = nullptr; doOpenVideoFileFailed(); goto end; } //存储pcm数据 int out_linesize = out_sample_rate * audio_tgt_channels; //out_linesize = av_samples_get_buffer_size(NULL, a